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Heavy metal complex compounds of ortho-hydroxy-azo-perimidine dyestuffs

US 1,746,940 A · Inventors: LUDWIG ZEH et al.

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  • Granted February 11, 1930. A patent granted before 1976 lasted at most 17 years from grant, so its term ended by February 11, 1947.
  • We check US rights only. Old patents can still inspire new ones: improvements may be patentable.
FiledOctober 18, 1927
GrantedFebruary 11, 1930
Term endedFebruary 11, 1947
Application number—
Classification (CPC)C09B45/14
Length4 pages

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Official USPTO records

Full published documentText and every drawing sheet as a PDF.USPTOFile historyStatus, office actions, notices, fee records and petitions.USPTO Patent CenterPatent Public Search recordSearchable full text and bibliographic data.USPTO

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